metamorphic

Weathered quartz-rich metamorphic rock, possibly quartzite

Quartzite; predominantly quartz (SiO₂), with minor feldspar, mica, and iron-oxide staining

AI-generated identification · may be incorrect

Hardness about 7 Mohs; tan, cream, and gray coloring with rusty brown weathering; vitreous to dull luster and a massive, granular texture. Quartzite lacks prominent cleavage and typically fractures irregularly or conchoidally.

Identified August 11, 2026More metamorphic →

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At a glance

Common name: Weathered quartz-rich metamorphic rock, possibly quartzite
Scientific name: Quartzite; predominantly quartz (SiO₂), with minor feldspar, mica, and iron-oxide staining
Category: metamorphic
Identified: August 11, 2026
Method: Standard

AI Estimated Value

About $5–$25 for a common hand specimen; larger, distinctive, or well-labeled specimens may sell for $30–$100.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed when quartz-rich sandstone was deeply buried and recrystallized under heat and pressure, commonly during regional mountain-building. Its exact geological age cannot be determined from the photograph.

Uses & applications

Used as crushed stone, road aggregate, building stone, countertops, and decorative material; attractive specimens may be collected but are generally low value.

Geological facts

Quartzite is harder and more tightly fused than its sandstone precursor; individual sand grains may be difficult to distinguish. The irregular surface and iron staining suggest substantial weathering.

Field identification & locations

Identify it by its very hard, quartz-rich texture and inability to scratch easily with a steel knife; dilute acid should not fizz unless carbonate minerals are present. Common in metamorphic mountain belts worldwide, including the Appalachians, Rocky Mountains, and Precambrian shields.